Scientists have conducted a genetic study to see how certain sections of DNA can control whether a person's skin burns or tans. The goal of this study, which was published in Nature Communications, is to not only better understand and predict an individual's response to sunlight, but to also help with understanding the onset of cancer.
The large genome-wide association study (GWAS) included 176,678 participants who were all of European ancestry. The researchers used data from the UK Biobank, a data source that has information about people's health and well-being, when conducting their GWAS to identify ten novel associations and replicate ten genes that had been previously associated with pigmentation-related phenotypes, or easily tanned skin.
After retrieving 121,296 individuals' genotype data from the UK Biobank, researchers split this up into two groups in accordance to the skin's ability to tan. They further conducted genome-wide association analysis with 8,351,141 single nucleotide polymorphisms (SNP) with an assumption of an additive genetic model that has sex included as covariate.
In an interview with The Independent, the lead author of the study, Mario Falchi, Ph.D., explained "Some of these genes involved in skin cancer probably have nothing to do with pigmentation. This may explain why the person next to you in the park gets completely red, and you get tanned, and you have exactly the same skin color. There is variability for people with the same pigmentation.”
After the scientists reviewed the genetic data they were able to retrieve from the Biobank, they were able to narrow down 10 new genetic regions that were linked with tanning. Several of the DNA variants that have been shown to be involved in tanning include: ASIP, EXOC2, HERC2, IRF4, MC1R, SLC45A2 and TYR.